The present invention relates to a transformer base mounted at the bottom of lighting poles or standards, as well as to a kit for forming such a base, and a method of making the base. Preferably, the base is of the breakaway type.
Lighting poles having breakaway transformer bases are known, wherein the transformer base, configured as a box of about 9″ to 17″ high, is adapted to break or shatter in response to lateral impact from a vehicle, thereby minimizing damage to the vehicle and its passengers. The transformer base may also provide access to wiring and sometimes house the luminaire transformer.
A prior art breakaway transformer base 10, shown in FIGS. 1-8, comprises a housing 12 having upper and lower pieces 14a, 14b formed of cast aluminum and welded together at 16. Bolt holes 18, 20 in the form of slots are formed at corners of the upper and lower pieces, respectively. The bolt holes 18 are located at the top of the upper piece 14a, and the bolt holes 20 are located at the bottom of the lower piece 14b. The lower bolt holes 20 receive bolts embedded in a concrete foundation (not shown), and the upper bolt holes receive bolts (not shown) for attaching a pole standard (not shown) to the base. The height of the base is about 17″. Variations in anchor bolt and pole bolt circle diameters D1, D2 necessitate that several sizes of the transformer base be offered in order to cover the dimensional variations. That, in turn, requires separate tooling for differently-sized cast pieces 12, 14, and the need to maintain a relatively large inventory of the cast pieces.
It would be desirable therefore to provide a transformer base, preferably of the breakaway type, which has lower tooling requirements and smaller inventory maintenance.
It would also be desirable to provide a transformer base, especially of the breakaway type, which provides greater access to the base interior and/or which can be assembled in the field by the end user.